Eelke Folmer

Game accessibility: a survey

Over the last three decades, video games have evolved from a pastime into a force of change that is transforming the way people perceive, learn about, and interact with the world around them. In addition to entertainment, games are increasingly used for other purposes such as education or health. Despite this increased interest, a significant number of people encounter barriers when playing games due to a disability. Accessibility problems may include the following: (1) not being able to receive feedback; (2) not being able to determine in-game responses; (3) not being able to provide input using conventional input devices. This paper surveys the current state-of-the-art in research and practice in the accessibility of video games and points out relevant areas for future research. A generalized game interaction model shows how a disability affects ones ability to play games. Estimates are provided on the total number of people in the United States whose ability to play games is affected by a disability. A large number of accessible games are surveyed for different types of impairments, across several game genres, from which a number of high- and low-level accessibility strategies are distilled for game developers to inform their design.

Indoor Human Navigation Systems: A Survey

Whereas outdoor navigation systems typically rely upon GPS, indoor systems have to rely upon dierent techniques for localizing the user, as GPS signals cannot be received indoors. Over the past decade various indoor navigation systems have been developed. This paper provides a comprehensive overview of existing indoor navigation systems and analyzes the dierent techniques used for: (1) locating the user; (2) planning a path; (3) representing the environment; and (4) interacting with the user. Our survey identies a number of research issues that could facilitate large scale deployment of indoor navigation systems.

Blind hero: enabling guitar hero for the visually impaired

Very few video games have been designed or adapted to allow people with vision impairment to play. Music/rhythm games however are particularly suitable for such people as they are perfectly capable of perceiving audio signals. Guitar Hero is a popular rhythm game yet it is not accessible to the visually impaired as it relies on visual stimuli. This paper explores replacing visual stimuli with haptic stimuli as a viable strategy to make games accessible. We developed a glove that transforms visual information into haptic feedback using small pager motors attached to the tip of each finger. This allows a blind player to play Guitar Hero. Several tests have been conducted and despite minor changes to the gameplay, visually impaired players are able to play the game successfully and enjoy the challenge the game provides. The results of the study also give valuable insights on how to make mainstream games blind-accessible.

Bridging patterns: An approach to bridge gaps between SE and HCI

Adding usability improving solutions during late stage development is to some extent restricted by the software architecture. However, few software engineers and human-computer interaction engineers are aware of this important constraint and as a result avoidable rework is frequently necessary. In this paper we present a new type of pattern called a bridging pattern. Bridging patterns extend interaction design patterns by adding information on how to generally implement this pattern. Bridging patterns can be used for architectural analysis: when the generic implementation is known, software architects can assess what it means in their context and can decide whether they need to modify the software architecture to support these patterns. This may prevent part of the high costs incurred by adaptive maintenance activities once the system has been implemented and leads to architectures with better support for usability.

The user as a sensor: navigating users with visual impairments in indoor spaces using tactile landmarks

Indoor navigation systems for users who are visually impaired typically rely upon expensive physical augmentation of the environment or expensive sensing equipment; consequently few systems have been implemented. We present an indoor navigation system called Navatar that allows for localization and navigation by exploiting the physical characteristics of indoor environments, taking advantage of the unique sensing abilities of users with visual impairments, and minimalistic sensing achievable with low cost accelerometers available in smartphones. Particle filters are used to estimate the users location based on the accelerometer data as well as the user confirming the presence of anticipated tactile landmarks along the provided path. Navatar has a high possibility of large-scale deployment, as it only requires an annotated virtual representation of an indoor environment. A user study with six blind users determines the accuracy of the approach, collects qualitative experiences and identifies areas for improvement.

A framework for capturing the relationship between usability and software architecture

Usability is increasingly recognized as an essential factor that determines the success of software systems. Practice shows that for current software systems, most usability issues are detected during testing and deployment. Fixing usability issues during this late stage of the development proves to be very costly. Some usability-improving modifications such as usability patterns may have architectural implications. We believe that the software architecture may restrict usability. The high costs associated with fixing usability issues during late-stage development prevent developers from making the necessary adjustments for meeting all the usability requirements. To improve upon this situation, we have investigated the relationship between usability and software architecture to gain a better understanding of how the architecture restricts the level of usability. Our article makes a number of contributions; a framework is presented that expresses the relationship between usability and software architecture. The framework consists of an integrated set of design solutions such as usability patterns and usability properties that have been identified in various cases in industry, modern day software and literature surveys. These solutions, in most cases, have a positive effect on usability but are difficult to retrofit into applications because they have architectural impact. Our framework may be used to guide and inform the architectural design phase. This may decrease development costs by reducing the amount of usability issues that need to be fixed during the later stages of development. Copyright

VI-Tennis: a vibrotactile/audio exergame for players who are visually impaired

Lack of physical activity is a serious health concern for individuals who are visually impaired as they have fewer opportunities and incentives to engage in physical activities that provide the amounts and kinds of stimulation sufficient to maintain adequate fitness and to support a healthy standard of living. Exergames are video games that use physical activity as input and which have the potential to change sedentary lifestyles and associated health problems such as obesity. We identify that exergames have a number properties that could overcome the barriers to physical activity that individuals with visual impairments face. However, exergames rely upon being able to perceive visual cues that indicate to the player what input to provide. This paper presents VI Tennis, a modified version of a popular motion sensing exergame that explores the use of vibrotactile and audio cues. The effectiveness of providing multimodal (tactile/audio) versus unimodal (audio) cues was evaluated with a user study with 13 children who are blind. Children achieved moderate to vigorous levels of physical activity- the amount required to yield health benefits. No significant difference in active energy expenditure was found between both versions, though children scored significantly better with the tactile/audio version and also enjoyed playing this version more, which emphasizes the potential of tactile/audio feedback for engaging players for longer periods of time.

Vi-bowling: a tactile spatial exergame for individuals with visual impairments

Lack of sight forms a significant barrier to participate in physical activity. Consequently, individuals with visual impairments are at greater risk for developing serious health problems, such as obesity. Exergames are video games that provide physical exercise. For individuals with visual impairments, exergames have the potential to reduce health disparities as they may be safer to play and can be played without the help of others. This paper presents VI Bowling, a tactile/audio exergame that can be played using an inexpensive motion-sensing controller. VI Bowling explores tactile dowsing: a novel technique for performing spatial sensorimotor challenges, which can be used for motor learning. VI Bowling was evaluated with six blind adults. All players enjoyed VI Bowling and the challenge tactile dowsing provided. Players could throw their ball with an average error of 9.76 degrees using tactile dowsing. Participants achieved an average active energy expenditure of 4.61 kJ/Min while playing VI Bowling, which is comparable to walking.

Component based game development: a solution to escalating costs and expanding deadlines?

Expanding deadlines and escalating costs have notoriously plagued the game industry. Although the majority of the game development costs are spent on art and animation, significant cost reductions and more importantly reductions in development time can be achieved when developers use off the shelf components rather than develop them from scratch. However, many game developers struggle with component integration and managing the complexity of their architectures. This paper gives an overview of developing games with components, presents a reference architecture that outlines the relevant areas of reuse and signifies some of the problems with developing components unique to the domain of games.

VR-STEP: Walking-in-Place using Inertial Sensing for Hands Free Navigation in Mobile VR Environments

Low-cost smartphone adapters can bring virtual reality to the masses, but input is typically limited to using head tracking, which makes it difficult to perform complex tasks like navigation. Walking-in-place (WIP) offers a natural and immersive form of virtual locomotion that can reduce simulation sickness. WIP, however, is difficult to implement in mobile contexts as it typically relies on bulky controllers or an external camera. We present VR-STEP; a WIP implementation that uses real-time pedometry to implement virtual locomotion. VR-STEP requires no additional instrumentation outside of a smartphones inertial sensors. A user study with 18 users compares VR-STEP with a commonly used auto-walk navigation method and finds no significant difference in performance or reliability, though VR-STEP was found to be more immersive and intuitive.